Overheating

How hot does the engine get in degrees F? I don't have the exact spec for your vehicle? Some vehicles, the radiator fan won't turn till about 220 degrees F. Some, if you turn on ac, the fan/s run. Some, if you unplug the coolant temp sensor, the fan/s will run. I did notice codes for radiator fan and coolant temp sensor, check for codes, even if the lamp isn't on. At atmospheric pressure, water boils around 212 degrees F. If you have a 15 pound radiator cap, as an example, for every pound of pressure increase raises the boiling point about three degrees. So, 45 degrees added to 212 degrees, that is the high 250s degrees, just to give you an idea about the boiling point. You could use jumper wires from the battery for voltage and ground to the fan, just to see if fan will run? At least you would know the fan itself is hopefully ok.

Buick says the first one comes on at 202 degrees Fahrenheit II turns on at 220 degrees Fahrenheit it has the Dex Cool Antifreeze with 180-degree thermostat but the fans are not coming on until 234 degrees and it has a new thermal knew everything coolant temperature sensor thermostats antifreeze is pumping good water it makes good Heat it doesn't burnt antifreeze that doesn't leak antifreeze it just boils it hot enough that it goes into limp mode

234 degrees F, if fans come on, that doesn't sound bad, too me. If the coolant is boiling, that doesn't sound good, does it? Other than what I've posted, I can't think of anything else at the moment.

I did look at pressure cap for your cooling system, it showed 18 psi. If your cooling system is under pressure it won't boil at 234 degrees F. Something isn't right? Just my opinion.

It does not boil at234º about 270ºit goes clear up to a 278 before it goes into limp mode

Sometimes for testing, I leave the thermostat out, hook-up everything. Make sure engine and radiator is full of coolant. W/o thermostat coolant flow is instant, can you check flow through the radiator? Another thought is combustion gases getting into the coolant?

Why would the bottom hose not be hot, while the top one is